This invention relates to the treatment of tobacco.
Much work has been done in the past in treating tobacco with the aim of improving its taste, aroma, burning and keeping qualities, the removal of undesirable components, and a variety of other improvements, mostly for commercial reasons. The present invention relates to the last of these reasons.
One of the treatments currently in use is impregnating raw tobacco leaf with liquified gas under pressure. Among the liquified gases used for the purpose are freon and carbon dioxide.
The use of freon, although advantageous because of lower pressure requirements, is less desirable than carbon dioxide due to potential health and pollution hazards. Liquid carbon dioxide, although not presenting these hazards, or at least not to the same degree, is a more difficult medium, as this process requires much higher pressure.
Equipment generally used with existing CO.sub.2 impregnating systems requires extensive factory space, very large CO.sub.2 storage and pumping equipment, complicated conveying and handling machinery, and taking it all together, a very expensive plant. In addition to that, the batch sizes to adequately meet output needs of a given operation are such, that the volume of the impregnating container discharges frozen (impregnated) tobacco in a "cake" size too large to be handled in subsequent processes without prior breaking into smaller volumed cakes (clumps). This, apart from requiring additional equipment, causes serious disintegration of tobacco leaf, producing a high percentage of fines (dust), reducing the sales value of the product.
The object of the present invention is the provision of an improved method and improved apparatus for treating tobacco leaf with an impregnating liquid.
Another object is the provision of apparatus so designed and constructed that the operation of such apparatus is largely automatic, requiring only a minimum of attention, and that the disintegration of the tobacco leaf being treated is greatly reduced as compared with prior systems.
Further objects are the provision of treating apparatus requiring less space, smaller CO.sub.2 storage, handling, and pumping equipment, avoiding the use of complex, very expensive overhead crane systems, relatively easier and less expensive maintenance and service requirements, and, in total considerably less expensive installation to provide the same hourly output of impregnated tobacco leaf compared to that of existing systems.